Hello,
I just did the throttle and EGR cleaning this past weekend and the car has been running better than it has in years. Now last night I went to put gas and put a bottle of STP fuel injection cleaner along with it and this morning on my way to work the car wanted to turn off it had a very low idle, the car never turned off but the RPMS got really low. Anyone have an idea what I could have done. There are no CEL lights at all. BTW the car is a 99 EX 4 cyl AT.

 

Honda recommends not to use anything in the fuel. I had a Civic that I put a cleaner in, I had to drain the tank.

 

Hey Jetsetter,
Thanks for your input I will definitely not do that again. I drove the car home after work and all is well now. It seems it burned off some carbon deposits from the additive or from the throttle cleaning itself I don't really know. I have taken it around a little bit and the car is running fine. I think I may have to adjust the idle speed a little cause its around 500 after it warms up. Thanks again.

 

Good to hear that your back up runing. Since you didn't drain the tank, I probably didn't have to either. Oh well, live and learn.

 

After cleaning up the throttle body, look in the DIY section for a post (by me) about setting the BASE idle and forcing it to re-learn. It may be that the throttle was full of crud, and someone just "adjusted the idle" to compensate. Hondas like to have their idle-control system set up just so.